Why do we care?

Statistics is the backbone of criminology and criminal justice.

• Number of arrests per year
• Number of crimes in each city
• Number of officers within a precinct
• Bureau of Justice Statistics (BJS)
• FBI’s Uniform Crime Report
• What and/or where else in criminology and criminal justice ?

Arrests Rate

One of the most common statistics used in criminology and criminal justice.

It signifies the number of people arrested within a population during a certain time frame - usually in a given year.

\[Arrest Rate = (Number of Arrest/Total Population) x Multiplier\]

is the process of gathering and analyzing data in a systematic way using procedures (i.e., methods) that are accepted across a discipline.

Sample vs. Population

• Any guesses?

• A Population is the universe of people, objects, or locations that researchers wish to study.

• A Sample is a subset pulled from the population in order to make generalizations about the universe of people, objects, or locations within that population.

Pop Quiz!

Which of the following is a sample?

a.) The number of women in the University

b.) The number of prisoners within a prison

c.) All of the people in the state of Michigan.

d.) A group of 100 police officers pull from a department

Replication

Thoughts?

Why would a statistics book emphasize replication?

• Replication is conducted for the purpose of determining if a study’s results hold when a new sample measures a previous study’s findings.

Hypothesis and Theories

Theory is a set of proposed and testable explanations about reality that are bound together by evidence.

Hypothesis a single proposition deduced from a theory, that must hold true in order for the theory itself to be considered valid.

Types of Scientific Research

Evaluation Research

• Examines the results of program to assess whether the programs are effective

Exploratory Research

• Examines issues that have been understudied and thus lack theoretical or empirical grounding

Descriptive Research

• Studies done for the purpose of describing a phenomena that occurs in a population

Probability Sampling is a sampling technique in which all people, objects, or areas in a population have a known chance of being selected into a sample.

Software for Statisitical Analysis

We will touch lightly on software in this class.

Specifically, we will be using R through Posit Cloud.

But we won’t dive into that until later in the semester.

Have a great day!